By MELANIE MCFARLAND, P-I TELEVISION CRITIC

Published 10:00 pm, Thursday, January 11, 2007

Violence and its inevitable byproduct, agony, make nightly guest appearances on prime-time television, but on "24" they're Jack Bauer's uncredited co-stars. He spreads them around with flair, jabbing sharp objects into nerve clusters, shooting kneecaps and threatening eyeballs.

With nothing less than the safety of the free world on the line, watching Jack (Kiefer Sutherland) inflict pain has become a key aspect in the series and, for some, a spectator sport.

Executive producers say Bauer earned the license to get away with this brutality, and, to a certain extent, they're right. We've watched him stop nukes, contain viruses and kick heroin within the space of a day.

Yet the show's creators were keenly aware the violent scenes aired in the wake of shocking, shameful photos of prisoner humiliation at Abu Ghraib. Recently, executive producer Howard Gordon told critics he had become aware "24" was having an influence on military interrogators.

So, what does it say about the fact that loving "24" means relishing, even slightly, Jack's efficiency and creativity with torture? Until recently, you could spar with that question or sit back and watch the crazy, safe in the knowledge that if a "24" scenario happened here, we'd be screwed anyway.

We have to ask ourselves that question, and there is no suitable answer beyond saying that viewers knew Jack would have to pay for his cruelty. The bill came due the moment Chinese government agents lassoed him.

He's back but he is a completely different animal on Day 6. That means some serious changes.

Granted, "24" still follows a reliable blueprint. You know Jack will complete his mission, there will be traitors in the White House and within the Counter Terrorist Unit, and you can lay a bet that the first villain we see isn't really the one pulling the strings. (And while we've left out the major and most of the minor spoilers, if you don't want to know anything besides that, stop reading now.)

Remember that "24" capitalized on our collective nightmare surrounding the threat of dire catastrophe. The simplest solution was to meet these crises with an unstoppable hero, a man in the same league as Jack Ryan or Jason Bourne or Ian Fleming's James Bond.

But on Day 6, the time to call upon Bauer to save the day has passed. Catastrophe is upon us -- explosions have been rocking cities and small towns for weeks, and they are expertly coordinated, claiming hundreds of lives. President Wayne Palmer (D.B. Woodside) will do anything to halt them.

Not a good time for the old "I'm gonna need a hacksaw" Jack to disappear, but he's history. We have a feeling we're gonna miss him. Twenty months in a prison wallpapered with human rights violations made Jack a flinching mess, with a web of scars crawling across his back and hands. Shattered, and worse, tired of living. Given the occasion to ruminate on death, he admits, "To be honest with you, it'll be a relief."

That's deep.

The silliest thrill on television can't afford to be deep, can it? Please, don't kid yourself. There is no inner wisdom hidden here. Without the explosions, egomaniacal madmen and intricate conspiracies within conspiracies, you'd be left with nothing but drinking game goofiness. The "24" universe is a place in which heroin withdrawal is a snap. How do you think the series handles post-traumatic stress disorder? This is a "shoot now, pay for therapy later" kind of show.

However, sticklers for logic, strict adherents to the laws of physics, time and lasting effects of physical trauma haven't had a good reason to check in yet, and they really shouldn't bother now.

Jack's stark psychological transformation is Day 6's central attraction, sure to give blogs fodder for endless discussion as the season rolls on. One wonders whether "24's" executive producers have taken Jack down this road as some sort of mea culpa for torture-happy seasons past. Or it simply could be a ham-fisted reminder that the beloved killing machine we cheered on for all these years is, in the end, a fragile human being.

More engaging, though, is the way in which fear, not terrorism, proves to be the ultimate destructive device. It darkens the judgment of honorable men, poisons the sanctity of the Constitution, makes people turn on each other and pushes America to the verge of becoming a police state dotted with detention camps.

So just put your intelligence on hold for an hour or four, and you'll be ecstatic at Day 6's beginning. All that remains is to see if "24" can build upon the tension and unbelievable moments making Sunday and Monday night's four-hour premiere the rocket-fueled thiller that it is.

It might even leave us with some thought-provoking statement by the time it's all over.

Saying that about television's silliest series isn't wise, but what the heck. We'll take the leap. Heaven knows "24" has asked us to make tougher ones than that.